Manatees are visiting Texas again but fossils suggest they may have been there thousands of years ago during the Ice Age

Manatees are once again turning up along the Texas coast this summer, surprising boaters and wildlife watchers with sightings of the gentle marine mammals in waters where they are considered uncommon. But their presence in Texas may be far older than anyone expected.

Recent sightings have been reported from Galveston to Port Mansfield, with some manatees spotted drinking from freshwater outflows and lingering around busy harbors and marinas. The Texas Marine Mammal Stranding Network is asking people to report sightings as researchers track where the animals are traveling.

Why Manatees visiting Texas?

Manatees are generally associated with Florida and warmer parts of the Gulf of Mexico. During summer, however, some travel hundreds of miles westward from Florida and Mexico as Gulf waters become warmer and suitable habitats expand. Freshwater sources are also important because manatees need to drink freshwater periodically.


That makes Texas an occasional summer destination for these slow-moving “sea cows.” But there is a surprising twist: scientists have found evidence that manatees were already present along the Texas coast during the Pleistocene, the geological period that includes the last Ice Age.

Ice Age fossils found along Texas coast

Research led by the University of Texas at Austin examined eight fossil specimens discovered along the Texas coast. Most came from McFaddin Beach near Port Arthur and Caplen Beach near Galveston, while another was recovered from Corpus Christi Bay. The fossils include jawbones and rib fragments and date to the Pleistocene.

Some of the fossils belonged to Trichechus manatus, the same species of manatee that visits Texas today. One upper jaw belonged to an extinct form of manatee, Trichechus manatus bakerorum. The findings provided the first fossil evidence of manatees in Texas and raised a bigger question: were the animals simply occasional visitors thousands of years ago, or did an ancient population actually live along the Texas coast?

The discovery is particularly puzzling because the Ice Age is generally associated with a much cooler climate. Modern manatees cannot tolerate prolonged exposure to cold water and generally need water temperatures above about 68 degrees Fahrenheit.

So how could they have survived in Ice Age Texas?

Scientists have proposed two possibilities. The coastal climate may have been warmer than previously believed, or ancient manatees may have been more tolerant of cooler conditions than their modern relatives. Another possibility is that they survived winter in warmer river outlets, much as manatees do today in parts of Florida and Mexico.

The ancient Texas coastline also looked very different. During the Ice Age, the Texas coast extended farther into the Gulf of Mexico and had wider river outlets and more coastal embayments. Those features could have provided suitable habitats for manatees.

Today, the animals face a very different problem when they reach Texas.

Some manatees are lingering around freshwater sources in busy marinas and harbors — precisely the places where boat traffic creates a serious collision risk. Wildlife officials are warning people not to feed manatees or deliberately provide them with freshwater, because encouraging the animals to remain in high-traffic areas could put them in greater danger.

For now, the summer visitors remain uncommon in Texas. But the modern sightings, combined with fossil evidence, suggest that the relationship between manatees and the Texas coast may stretch much farther back than previously imagined.

What looks like a strange modern migration may, in fact, be part of a much older story.